The large epidemiological study, led by Xiao-Ou Shu, M.D., Ph.D., was published online recently in the American Journal of Epidemiology.
Ginseng is a slow-growing perennial herb whose roots have been used in traditional Chinese medicine for more than 2,000 years. The two main classes of ginseng – red and white – have different biological effects, according to traditional Chinese medicine theory. White, or unprocessed, ginseng is used over long periods to promote general health, vitality and longevity. Red, or processed, ginseng provides a much stronger effect and is used for short periods to aid in disease recovery.
Both varieties of ginseng contain more than 30 chemicals, called ginsenosides, which have anti-tumor effects in cell culture and animal studies, suggesting that the herbs may provide specific benefits to cancer patients. In fact, ginseng use has been increasing among cancer patients in recent years, particularly in women diagnosed with breast cancer.
However, despite the encouraging laboratory findings, scientific analysis of ginseng's health benefits in patient populations has been lacking. "There is a lot of skepticism about herbal medicine," said Shu. "That is why we are taking the observational approach at this time to see whether there is any efficacy. If so, we can go to the next phase. … and eventually go to clinical trials."
Shu and colleagues assessed the effects of ginseng use in breast cancer survivors as part of a large epidemiological study, the Shanghai Breast Cancer Study, which has followed 1,455 breast cancer patients in Shanghai since 1996. For the current study, Shu and colleagues evaluated breast cancer patients for ginseng use both before and after their diagnosis of breast cancer. All patients who used ginseng had received at least one type of conventional cancer therapy (e.g., surgery, chemotherapy and/or radiotherapy).
Information on ginseng use prior to cancer diagnosis, which was available for every subject, was used to determine whether prior ginseng use predicted survival. At follow up – about three to four years after diagnosis – the researchers asked about ginseng use since diagnosis. That information, which was available only for survivors, was used to look at quality of life measurements – i.e., physical, psychological, social and material well-being.
Before diagnosis, about a quarter of patients (27.4 percent) reported using ginseng regularly. After diagnosis, that percentage jumped to 62.8 percent, the researchers found. They also found significant improvements in both survival and quality of life measures in patients who used ginseng. "When patients used ginseng prior to diagnosis, they tended to have higher survival," Shu explained. "Ginseng use after cancer diagnosis was related to improved quality of life."
The findings suggest that ginseng may provide tangible benefits to breast cancer survivors, but there are limitations to the study. The varieties and the methods of ginseng use and the use of other complementary and alternative therapies could not be fully accounted for in the analysis. Also, the quality of life measures exclusively relied on patient self-reporting.
Although side effects of ginseng use were not recorded in this study, Shu warned that the seemingly innocuous root can create problems when improperly used and should be taken with caution. "It's not a 'drug' in terms of being managed by the FDA, but it was used as a drug in traditional Chinese medicine," she said. "Any drug may have some side effects and may interact with other drugs. So, discuss with your primary care doctor before you decide to take ginseng roots or products."
Shu hopes to confirm and expand the current findings through continued collection of data in this patient population, from another ongoing study of 4,000 breast cancer patients, and eventually, in randomized clinical trials. Scientific study of complementary and alternative medicines is tricky though, said Shu. "Chinese traditional medicine is very individualized. It gives you different drugs based on your symptoms and your overall health. There is much to be learnt."
Other authors on the paper were Yong Cui, M.D., Hui Cai, M.D., Ph.D., Meng-Hua Tao, M.D., and Wei Zheng, M.D., Ph.D., from Vanderbilt and Yu-Tang Gao, M.D., from the Shanghai Cancer Institute. The research was supported by grants from the National Cancer Institute.
Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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